To me,
for this film only, the less scenes of Wayne, the better. I guarantee you, even if he does a good job, that most of the audience will say internally "oh, hi Ben Affleck."
But if he's shown more as Batman, then the audience doesn't have to suspend any type of plausibility of sorts. They can just see him as the character.
They can show more Wayne in the sequel. But having Wayne be a prominent character in here risks throwing the audiences' response to him off (He's a good Batman, but a P!ZZ poor Wayne. Where's Bale when you need him?)
I don't think that is fair for Affleck (he's getting enough flack as it is), and less screentime for Bruce means more time for Clark/Lois/Metropolis/ the international response to Superman
Again, I think he will nail "playboy Bruce" and I think he will also be a pretty solid "broody Bruce."
But also Bale created a certain expectation for the Bruce Wayne character. The audiences haven't bonded to this version of Wayne, and I don't think they'll do so easily, especially when they see Ben's face in the role. Something he can't help, unless he grows a mustache to throw the appearance off :P
Having an awesome BATMAN can create interest in his alter ego. But the other way around, I think isn't, as effective.
So yeah, I'd have one to 2 scenes with Bruce, and MAYBE 3 scenes with Batman in the film
I'd rather see him as an effective minor character, then one that eats up the film and character development of Clark/Lois/Perry.
